The present disclosure relates to the subject matter disclosed in German Application No. 101 41 153.7 of Aug. 17, 2001, which is incorporated herein by reference in its entirety and for all purposes.
The invention relates to a clamping and spreading device for the relative movement of two workpieces which have surfaces lying essentially parallel to a common plane, comprising a first holder, on which the first workpiece can be fixed, and a second holder, on which the second workpiece can be fixed, wherein the two holders are movable relative to one another.
Such a device is sold, for example, under the name VERIFIX by the Josef Bohle Stiftung and Co. KG, Haan, Germany. Furthermore, such a device is known by the name xe2x80x9cRigid Seaming Vacuum Padsxe2x80x9d from Pinske Edge, Plato, Minn., USA.
The object underlying the invention is to improve a clamping and spreading device specified at the outset in such a manner that this can be used in a simple manner comfortable for the operator.
This object is accomplished in accordance with the invention in that the first holder and the second holder are connected to one another via a guiding device so as to be displaceable and that the guiding device comprises an actuating element which is not only mounted on the first holder so as to be movable but is also mounted on the second holder so as to be movable and via which a relative movement of the two holders can be actuated.
Due to the fact that the two holders are connected to one another via the guiding device and, in addition, via the actuating element of the guiding device which is, in particular, of a rigid design, a relative movement between the two holders and, therefore, between respective fixed workpieces may be carried out in a concerted and simple manner in order to bring about, in particular, a clamping movement or a spreading movement. A good stability and rigidity of the device is achieved by the coupling of the two holders via the guiding device so that, in particular, any tilting of the two workpieces relative to one another can be prevented to a large extent.
A large path of displacement of the two holders relative to one another may be brought about via the movable mounting of the actuating element not only on the first holder but also on the second holder without the outer dimensions needing to be increased significantly as a result.
In this respect, it is provided, in particular, for the actuating element to be mounted on the first holder so as to be rotatable or rotatably displaceable relative to it. A corresponding moment may be exerted as a result of rotation in order to be able to act on the two holders with a force relative to one another in order to be able to carry out a clamping procedure or a spreading procedure as a result.
Furthermore, it is provided for the actuating element to be mounted on the second holder so as to be rotatably displaceable relative to it. The second holder is then displaced relative to the actuating element via a rotation of the actuating element and, therefore, the two holders may be displaced relative to one another. If the actuating element is also held on the first holder so as to be rotatably displaceable, a translational movement not only of the first holder but also of the second holder takes place during a rotation of the actuating element. If the actuating element is mounted so as to only be rotatable with respect to the first holder, no translational movement takes place in relation to it.
As a result of rotary actuation of the actuating element, the second holder may be favorably moved towards the first holder or away from the first holder depending on the direction of rotation. In this respect, it may also be provided for the first holder to itself move in a translational manner with respect to the actuating element.
It is particularly advantageous when the distance between the two holders can be adjusted infinitely via the actuating element in order to thus be able to set any optional distance and in order to facilitate constant action with a force during a clamping movement or spreading movement.
Furthermore, it is favorable when a specific distance between the two holders is determined via a specific position of the actuating element. As a result, a specific position need not be maintained by the actuating element being acted upon from outside with a force but rather a set distance between the two holders also remains fixed without any external action with a force.
In one embodiment which can be used in a simple manner, the actuating element comprises a spindle which is, in particular, of a rigid design and extends between the two holders.
In this respect, the spindle is, in particular, rotatably mounted so as to be non-translational with respect to the first holder. It is then sufficient to provide only one rotary sliding bearing, for example, via threads engaging in one another and, in particular, no oppositely directed threads need be provided in order to bring about a relative movement of the two holders via a rotation of the spindle.
In an alternative embodiment, the actuating element comprises a sleeve which is arranged so as to be rotatable on one holder or between the two holders and in relation to which at least one holder is displaceable. Such a sleeve may also be arranged between the holders in order to obtain a particularly space-saving design. As for the rest, such a device may also be designed with great symmetry, i.e. the actuating element may be arranged in a plane of symmetry in order to minimize any tilting moment of the entire device.
In this respect, it is particularly provided for the holder or holders, with respect to which the sleeve is arranged so as to be rotatable, to have a respective, non-rotatable spindle for engaging the sleeve. A relative displacement of the holders towards one another or away from one another may then be achieved via actuation and, in particular, rotation of the sleeve as a result of the combination spindle/sleeve and with formation of a rotary sliding bearing, in particular, via threads engaging in one another.
The actuating element is advantageously provided with at least one threaded section which engages in a corresponding threaded section of an associated holder for the displaceable guidance of this holder. As a result, a rotary sliding bearing may be formed in a technically simple manner and so a rotary movement of the actuating element can be converted into a translational movement, wherein a clamping force or spreading force can be exerted on workpieces via torque on the actuating element.
In this respect, at least the second holder is favorably provided with an internal thread for engaging in an external thread of the actuating element in order to be able to displace the second holder in relation to the first holder by forming a corresponding rotary sliding bearing. In this respect, it may be provided for the first holder to also be provided with a rotary sliding bearing in order to be able to displace not only the first holder but also the second holder in relation to it in a translational manner during rotation of the actuating element.
It is particularly advantageous when the actuating element is provided with a handle. Such a handle, such as, for example, a wooden handle which sits well in the hand, may be grasped by an operator with one hand so that the operator can get a good grip on it and thus can exert a high torque on the actuating element and, therefore, can exert a correspondingly high clamping force or spreading force on workpieces.
In a variation of one embodiment, the handle is arranged at one end of the actuating element outside an intermediate area between the two holders so that unhindered engagement on the handle is possible.
In an alternative embodiment, the handle is arranged in the intermediate area between the two holders. As a result, the outer dimensions of the device are minimized and, in addition, a symmetric construction may be achieved, by means of which tilting moments of the device are, for example, minimized in relation to workpieces.
It is provided, in particular, for a first threaded section of the first holder or the actuating element and a second threaded section of the second holder or the actuating element to be designed such that the two holders are displaceable relative to one another during rotation of the actuating element. During a rotary actuation of the actuating element, not only the first holder but also the second holder are moved in a translational manner, namely towards one another in order to generate, for example, a clamping force or away from one another in order to generate, for example, a spreading force. A corresponding threaded design may be achieved by way of oppositely directed threaded sections or ones with different pitches.
It is particularly advantageous when the guiding device comprises at least two spaced guide rails, via which the two holders are guided for displacement relative to one another. As a result, a high stability of the device is achieved since the two holders are coupled to one another several times, namely via the actuating element and the two guide rails. As a result, a levering moment, with which the device engages on workpieces, is minimized. Furthermore, an operator can exert a force on two workpieces in a simple and secure manner, for example, a clamping force and a spreading force, namely in a largely symmetric manner in order to keep troublesome tilting moments of the device in relation to the workpieces small.
In this respect, a guide rail is advantageously provided with an end stop in order to prevent any detachment of a holder from the device.
An inventive device may be produced in a simple and inexpensive way when the first holder and the second holder each have a guide bracket, on which the guide rails are guided or fixed. As a result, the guidance of the two holders may be designed separately from the holding function of the two holders. For example, the holders may be magnetic holders, vacuum suction means or holders which can be fixed on a workpiece in a form-locking, frictional or adhesive manner. In order to form a guiding device, these holders do not have to be substantially modified and, in particular, their holding function is not affected by the design of a guiding device. In addition, certain dimensions which are advantageous for the functioning of the device may be modified as a result of a separate formation of guide brackets. For example, the guide rails may be xe2x80x9cloweredxe2x80x9d via the guide brackets in order to, in particular, keep the lever arm of the guide rails and thus of the entire device slight in relation to workpieces.
In this respect, the guide brackets of the two holders are advantageously of essentially the same design in order to keep the production costs low.
Furthermore, it is advantageous when a guide bracket is designed with respect to its outer configuration to be essentially symmetric to a longitudinal axis of the device. As a result, tilting moments of the device are minimized in relation to a workpiece.
Furthermore, it is advantageous when a guide bracket is designed such that the guide rails are located beneath the actuating element with respect to a holding plane facing the workpiece surface. In this way, the lever arm of the device, which is present in relation to a workpiece surface, is reduced.
In a particularly advantageous variation of one embodiment, a spindle is mounted as actuating element on the first guide bracket of the first holder and the second guide bracket of the second holder. The spindle is, in particular, mounted on the first guide bracket so as to be rotatable and mounted on the second guide bracket so as to be rotatably displaceable.
With such an embodiment, it is, in addition, favorable when the guide rails are fixed on the first holder so that during a rotary actuation of the spindle only the second holder is displaced in relation to the spindle via the guide bracket.
In order to be able to minimize the lever arm of the device in relation to workpieces, the spaced guide rails are favorably arranged in the area of a transverse end of a guide bracket.
Furthermore, it is favorable when the actuating element is mounted between the guide rails parallel to them in order to, on the one hand, reduce the production costs and, on the other hand, achieve a good and stable coupling between the two holders.
In a variation of one embodiment, a lever for compensating for differences in the levels of the workpieces is guided for displacement on a guide rail. When two workpieces, for example, two plates are clamped to one another by means of the inventive device, it is possible that in the area of the join small differences in levels are present, i.e. the plates do not lie exactly flush in this area. Such small differences in levels may be compensated at the join transition with such a lever which presses on the plates in the area where they join.
For this purpose, the lever is, in particular, pivotable with a contact surface in the direction of the surface of the workpieces so that a slight tilting of the two workpieces relative to one another can be brought about as required via the contact surface in order to obtain a flush transition via a join.
Furthermore, it is favorable when the contact surface is essentially located on a plane defined by the two holders in a compensation position of the lever in order to obtain a flush adjustment.
It is, furthermore, favorable when the lever has a free space on its contact surface. This free space can accommodate glue when the two workpieces are intended to be adhered or glued via the join. Furthermore, it is possible via this free space to supply adhesive material or glue to the join, for example, from above without the lever needing to be released.
It may be favorable when the guiding device is biased to reduce the guidance play, for example, in that the guide rails are bent. This has functional advantages since the corresponding bearings need to be of a less exact design and, nevertheless, a high clamping force or spreading force can be achieved.
With the inventive device, the most varied of holders can be used. In the case of magnetic materials, magnetic holders can, for example, be used. It may also be provided for the holder to comprise a block which is screwed, for example, to a workpiece. Particularly for plate-like components with a smooth surface, it is advantageous when the holder comprises a vacuum suction device which can adhere securely to a workpiece via underpressure.
The following description of preferred embodiments serves to explain the invention in greater detail in conjunction with the drawings.